Cohort Profile: The Dutch Hunger Winter Families Study

Historical setting The winter of 1944–45 is known as the ‘Hunger Winter’ in The Netherlands, which was occupied by the Germans in May 1940. Beginning in September 1944, Allied troops had liberated most of the South of the country, but their advance towards the North came to a stop at the Waal and Rhine rivers and the battle of Arnhem. In support of the Allied war effort, the Dutch government in exile in London called for a national railway strike to hinder German military initiatives. In retaliation, in October 1944, the German authorities blocked all food supplies to the occupied West of the country. Despite the war, nutrition in The Netherlands had generally been adequate up to October 1944. Thereafter, food supplies became increasingly scarce. By November 26, 1944, official rations, which eventually consisted of little more than bread and potatoes, had fallen below 1000 kcal per day, and by April 1945, they were as low as 500 kcal per day. Widespread starvation was seen especially in the cities of the western Netherlands. Food supplies were restored immediately after liberation on May 5, 1945. On the basis of these historical data it is possible to accurately define the beginning and the end of the famine period. The famine affected fertility, weight gain during pregnancy, maternal blood pressure, infant size at birth and central nervous system development. The reduction in fertility was greater among manual workers than among those in other occupations. A decline in mean birth weight of 300 g was seen among those exposed to maternal undernutrition during the third trimester. After liberation and the restoration of food supplies, birth weights and other measures of infant size rapidly rebounded to pre-famine levels. Because the Dutch population was typically well fed before and after the Hunger Winter, the circumstances of the famine created what can be regarded as a ‘natural experiment’ in which exposure to famine is assigned based on an individual’s time and place of birth. This design was used to examine how maternal undernutrition during specific gestational time windows may affect the subsequent life course of offspring who experienced the famine in-utero.